Monoazo pyrazolone dyes



United States Patent 3,424,742 MONOAZO PYRAZOLONE DYES Arthur D. Jarrett, Belmont, Mass., assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware No Drawing. Continuation-impart of application Ser. No

209,230, July 11, 1962. This application Nov. 5, 196,4, Ser. No. 409,282 1 US. Cl. 260-162 7 Claims Int. Cl. G03c 7/30; C09b 29/26 ABSTRACT OF THE DISCLOSURE Azo dyes of the formula:

wherein each Y is selected from among orthoand paradihydroxyphenyl radicals; each Ar is a phenylene or naphthalene group; M and X are each alkylene groups; n and p each is an integer from 0 to 1 inclusive; and each of R and R is a hydrogen or alkyl radical, and R and R can be joined together as a divalent aliphatic radical. These dyes are particularly useful as photographic developing agents.

This application is a continuation-in-part of application Ser. No. 209,230, filed July 11, 1962, now US. Patent No. 3,183,090, issued May 11, 1965.

This invention relates to novel chemical compositions of matter and 'more particularly to novel dye developers especially useful in the development of photosensitive silver halide elements and methods for preparing them.

It is one object of the present invention to provide novel processes and compositions for the development of silver halide emulsions, in which novel colored developing agents are used,

Another object is to provide novel processes and compositions for the development of silver halide emulsions, in which the novel developing agent is capable of developing an exposed silver halide emulsion and imparting a reversed or positive colored image of the developed image to a superposed image-receiving material.

A further object is to provide novel products, processes and compositions suitable for use in preparing monochromatic and multichromatic photographic images.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the processes involving the several steps and the relation and order of one or more of such steps with respect to each of the others, and the products and compositions possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

The objects of this invention may be accomplished by the use of certain novel dyes which have the ability to develop images present in an exposed silver halide emul- 3,424,742 Patented Jan. 28, 1969 sion; thus, they may be referred to as dye developers. These novel dyes or dye developers will be further described hereinafter.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description.

The photographic processes and compositions disclosed herein are particularly useful in the treatment of an exposed silver halide emulsion, whereby 'a positive dye image may be imparted to another element, herein referred to as an image-carrying or image-receiving element.

US. Patent No. 2,983,606, issued May 9, 1961 to Howard G. Rogers, discloses diffusion transfer. processes wherein a photographic negative material, such as a photographic element comprising an exposed silver halide emulsion, is developed in the presence of a dye developer to impart to an image-receiving layer a reversed or positive dye image of the developed image by permeating into said emulsion a suitable liquid processing I composition and bringing said emulsion intlo superposed relationship with an appropriate image-receiving layer. The inventive concepts herein set forth provide novel dye developers for use in such processes.

In carrying out the process of this invention, a photosensitive element containing a silver halide emulsion is exposed and wetted with a liquid processing composition, for example by immersing, coating, spraying, flowing, etc., in the dark, and the photosensitive element superposed prior to, during or after wetting, on image-receiving element, In a preferred embodiment, the photosensitive element contains a layer of dye developer, and the liquid processing composition is applied to the photosensitive element in a uniform layer as the photosensitive element is brought into superposed position with an image-receiving element. The liquid processing composition permeates the emulsion to provide afsolution of dye developer substantially uniformly distributed therein. As the exposed silver halide emulsion is developed, the oxidation product of the dye developer is immobilized or precipitated in situ with the developed silver, thereby providing an imagewise distribution of unoxidized dye developer dissolved in the liquid processing composition. This immobilizaton is apparently due, at least in part, to a change in the solubility characteristics of the dye developer upon oxidation, and especially as regards its solubility in alkaline solutions. It may also be due, in part, to a tanning effect on the emulsion by the oxidized developing agent. At least part of this imagewise distribution of unoxidized dye developer is transferred, by imbibition, to a superposed image-receiving layer. The image-receiving layer receives a depthwise diffusion, from the emulsion, of unoxidized dye developer, without appreciably disturbing the imagewise distribution thereof, to provide a reversed or positive, colored image of the developed or negative image. The image-receiving element may contain agents adapted to mordant or otherwise fix the diffused, unoxidized dye developer. Imbibition periods of approximately one minute have been found to give good results, but this contact period may be adjusted where necessary to compensate for variations in temperature or other conditions. The desired positive image is revealed by stripping the image-receiving layer from the silver halide emulsion at the end of the imbibition period.

The dye developers of this invention may be utilized in the photosensitive element, for example in, on or behind the silver halide emulsion, or they may be utilized in the wherein R and R each may be hydrogen or an aliphatic, image-receiving element or in the liquid processing come.g., alkyl or hydroxyalkyl, radical, and R and R toposition. In a preferred embodiment, a coating or layer gether may be a. divalent aliphatic radical, e.g., a pentaof the dye developer is placed behind the silver halide methylene radical completing, with the nitrogen atom, a

emulsion, i.e., on the side of the emulsion adapted to be 5 piperidine ring. Preferably R and R each contains no located most distant from the photographed subject when more than 12 to 15 carbons. The arylene group Ar may,

the emulsion is exposed and preferably also adapted to be if desired, be substituted, by, for example, alkyl radicals. most distant from the image-receiving layer when in As examples of alkylene radicals comprehended by the superposed relationship therewith. Placing the dye develradicals M and X, mention may be made of radicals such oper behind the emulsion layer, as in the preferred emas CH CH bodiment, has the advantage of providing increased con- CH3 trast in the positive image, and also minimizes any light- I filtering action by the colored dye developer. In this pre- CHPCIPCHP ferred embodiment, the layer of dye developer may be and 2 z 2- Theprefefl'ed embodiment is applied by using a coating solution containing about 0.5 a lower alkylene group, -gless than 5 carbons, and more to 8%, by weight, of the dye developer. Similar concenpreferably an ethylene group. It should be understood that trations may be used if the dye developer is utilized as a M nd X may be alkylene groups comprising 6 or more component of the liquid processing composition. In an carbon atoms provided that the resulting dye developer is especially useful mode of disposing the dye developers in Capable of being dissolved in the liquid Processing the photosensitive elements, the dye developer is dissolved position, and its oxidation Product rendered immobilein a water-immiscible solvent and then dispersed in a AS examples of dye developers within the scope of this gelatin coating solution. invention, mention may be made of:

The liquid processing composition which is used in the OH processes herein disclosed comprises at least an aqueous f solution of an alkaline compound, for example, diethyl- OH2 -N=N -bNCHrCH2OH20H amine, sodium hydroxide or sodium carbonate, and may contain the dye developer. In some instances, it may con- 110 H tain an additional silver halide developing agent. If the N I liquid processing composition is to be applied to the emul- 011 the type which, when spread over a water-absorbent base, will form a relatively firm and relatively stable film. A preferred film-forming material is ahigh molecular weight (1) 1 (4 hydroquinonylethylphenyl) 3 [N 'y I -CH sion by being spread thereon, preferably in a relatively 30 thin, uniform layer, it may also include a viscosity-increasing compound constituting film-formin-g material of H CH2 polymer such as a polymeric, water-soluble ether inert to hydroxypropyl) carbamyl] 4 (3" hydroquinonylan alkali solution, as, for example, a hydroxyethyl cellumethylphenylazo)-5-pyrazolone om-om-om-G-zwn TH-c-n-om-om-om-om N HO N/ OH I (iJH GIL-0H,-

lose or sodium carboxymethyl cellulose. Other film-form- (2) 1 (4' hydroquinonylethylphenyl) 3 (N,n-butyling materials or thickening agents whose ability to incarbamyl) 4 (4" hydroquinonylpropylphenylazo)- crease viscosity is substantially unaffected when left in s-pyrazolone solution for a long period of time may also be used.

The dye developers of this invention may be represented by the formula: OH O H f I N/ AI-(M) n Y 0H wherein W is a carbamyl radical, Ar is an arylene group, preferably a phenylene or naphthylene group and each Ar may be the same or different, M and X are alkylene radicals, n "and p each are 0 or 1, and each Y is an orthoor l para-dihydroxyphenyl radical. CHPCH The carbamyl radical W may be represented as 11 (26) 1 (4 hydroquinonylmethylphenyl) 3 (N- ethylcarbamyl) 4 (4" methyl 6" hydroquinonylpropylnaphthylazo)--pyrazo1one I @-CH2CH2 l on on I l CHz-CH CHa (27) 1 [4" (13 [4"' methyl 2",5 dihydroxyphenyl] ethyl) phenyl] 3 (N pentamethylene)- carbamyl 4 (3" hydroquinonyl ethylphenylazo)- 5-pyrazolone (28) 1 [4" 3 [2"' chloro 3",4 dihydroxyphenyl] ethyl) phenyl] 3 (N,N dimethylcarbamyl 4 (4 hydroquinoyl ethylphenylazo) 5- pyrazolone' (29) l (4 hydroquinonylpropylphenyl) 3 [N fi- (hydroxyethyl) carbamyl] 4 [3" (3',4-dihydroxyphenyD-ethylphenylazo] -pyrazolone The novel dye developers of this invention may be prepared by diazotizing and coupling a compound of the formula:

(B) Y --(X) Ar-NH into a compound of the formula:

ll 0 z 1104 1lr(M)n-Y wherein Y is the protected derivative of the orthoor para-dihydroxyphenyl group, preferably the acylated derivative thereof, Z is an alkyl radical, X, M, n, p and Ar have the same meaning as above, replacing the 3- carboxylate group with a 3-carbamyl group by reacting the product with an excess of ammonia or an amine which reactant also removes in the same step the protective groups on Y to produce the hydroxyl compounds.

Compounds within Formula B and the corresponding dihydroxyphenyl compounds are disclosed and claimed in U.S. Patent No. 3,019,254, issued Jan. 30, 1962 to Milton Green and Helen P. Husek, and in the copending application of Elkan R. Blout, Milton Green, Howard G. Rogers, Myron S. Simon and Robert B. Woodward, Ser. No. 98,287, filed Mar. 27, 1961 and now U.S. Patent No. 3,139,283; the copending application of Myron S. Simon, Ser. No. 196,463, filed May 21, 1962 (now U.S. Patent No. 3,134,811, issued May 26, 1964); and the copending application of Myron S. Simon, Ser. No. 196,464, filed May 21, 1962 and now abandoned.

The coupler compounds of Formula C are disclosed and claimed in the copending application of Milton Green and Phylis T. Moore, Ser. No. 130,489, filed Aug. 10, 1961 and now abandoned.

The process of preparing 3-carbamyl-pyrazolone dyes from the corresponding 3-carboxylate-pyrazolone dye is disclosed and claimed in the copending application of Milton Green, Ser. No. 130,467, filed Aug. 10, 1961 (now abandoned).

The following nonlimiting examples illustrate the preparation of dye developers within the scope of this invention:

EXAMPLE 1 To a suspension of 7 g. of m-aminophenyl-hydroquinone-0,0'-diacetate hydrochloride in 200 ml. of water, was added, with stirring, 8 ml. of concentrated hydrochloric acid. The resulting suspension is rapidly cooled to 0-5 C. by a butyl Cellosolve-carbon dioxide bath and a solution of 1.5 g. sodium nitrite in 30 ml. of water is added dropwise to the cooled suspension. Stirring is continued for one hour and the suspension is added dropwise, without filtering to a stirred suspension of 9.3 g. of 1-[p-(2,5'- diacetoxyphenylpropyl)-phenyl] 3 carbethoxy 5 pyrazolone, 7 g. of sodium carbonate, 400 ml. of acetone and 300 ml. of water and ice at a temperature less than 15 C. Stirring was continued for one hour after which the product, l- [4-propyl-4- (2",5"-diacetoxyphenyl) -phenyl] 3-carbethoxy-4- [3 (2",5"-diacetoxyphenyl) -pheny1azo] 5-pyrazolone, was collected by suction filtration, washed with water and dried under vacuum. 5 g. of the product was placed in a three-necked flask, fitted with a dropping funnel, a mechanical stirrer and a nitrogen inlet-outlet tube. The system was flushed out with nitrogen and 50 ml. of deaerated hexylamine was added from the dropping tube. Stirring was continued under nitrogen and the flask was heated on a steam bath for 4 hours. Excess amine was then removed by vacuum distillation and the product precipitated by the addition of dilute, deaerated hydrochloric acid. The gummy product was then washed with water and dissolved in methyl Cellosolve, precipitated into dilute hydrochloric acid, filtered, and again washed with water. The product was again dissolved in methyl Cellosolve, deaerated with nitrogen and added to a solution of 5 g. of sodium hydroxide in 500 ml. of water which had been deaerated with nitrogen for 30 minutes. The product was precipitated by the addition of gaseous carbon dioxide and was filtered and washed with water. The solid was redissolved in methyl Cellosolve and reprecipitated into dilute hydrochloric acid. The product, 1-(4-hydroquinonylpropylphenyl) 3 (N,n-hexylcarbamyl)-4-(3"- hydroquinonylphenylazo)-5-pyrazolone, was collected by suction filtration, washed with water and dried in a vacuum. The product showed a melting point of 122-125 C. with decomposition.

13 EXAMPLE 2 3-(2',5' diacetoxybenzyl) aniline hydrochloride was diazotized and coupled into 1-(4'-[2",5" diacetoxyphenylethyl]-phenyl)-3-carbethoxy-5-pyrazolone. The resulting compound was treated with 1-amino-3-propanol in a nitrogen atmosphere. The resulting product, 1-(4'-hydroquinonylethylphenyl) 3 [N (v-hydroxypropyl)carbamyl]-4-(3"-hydroquinonylmethylphenylazo) pyrazolone, melted at 139-145 C.

EXAMPLE 3 4-(2',5-diacetoxybenzyl)-aniline hydrochloride was diazotized and coupled into 1-[4'-(2",5"-diacetoxyphenylethyl)-phenyl1-3-carbethoxy-5 pyrazolone. The resulting solid was treated with 1-amino-3-propanol in a nitrogen atmosphere. The resulting product, 1-(4'-hydroquinonylethylphenyl) 3 [N-(v-hydroxypropyl)-carbamyl]-4- (4" hydroquinonylmethylphenylazo) 5 pyrazolone, melted at 185-187 C.

EXAMPLE 4 m-Aminophenyl-hydroquinone-0,0 diacetate hydrochloride was diazotized and coupled into 1-[4'-(2",5"- diacetoxyphenylpropyl)-phenyl] 3 car-bethoxy-S-pyrazolone. The resulting solid was treated with n-propylamine in a nitrogen atmosphere. The resulting product, 1-(4- hydroquinonylpropylphenyl) 3 (N,n-propylcarbamyl)- 4-(3"-hydroquinonylphenylazo)-5-pyrazolone, melted at 133-l38 C.

EXAMPLE 5 3-(2,5-bisacetoxybenzyl)-aniline hydrochloride was diazotized and coupled into 1 [4' (2",5 bisacetoxyphenylpropyl)-phenyl]-3-carbethoxy-5 pyrazolone. The resulting product was treated with ethanol and ammonia in a nitrogen atmosphere. The resulting product, 1-(4- hydroquinonylpropylphenyl) 3 carbamyl-4-(3"-hydroquinonylphenylazo)-5-pyrazolone, melted at 151-155 C.

EXAMPLE 6 p-Aminophenethyl-hydroquinone-0,0'-diacetate hydrochloride was diazotized and coupled into 1-(4'-[2", 5"- diacetoxyphenylethyl]-phenyl)-3-carbethoxy 5 pyrazolone. The resulting compound was treated with hexylamine in a nitrogen atmosphere. The resulting product, 1-(4'-hydroquinonylethylphenyl)-3-(N,n-hexylcarbamyl)-4 (4"- hydroquinonylethylphenylazo)-5-pyrazolone, melted at 128-132 C.

EXAMPLE 7 m-Aminophenylpropyl-hydroquinone-0,0'-diacetate hydrochloride was diazotized and coupled into l-(4'-[2",5"- diacetoxyphenylethyl]-phenyl) 3 carbethoxy-S-pyrazolone. The resulting compound was treated with hexylamine in a nitrogen atmosphere. The resulting product, 1- (4'-hydroquinonylethylphenyl)-3-(N,n-hexylcabamyl)- 4-(3" hydroquinonyl-propylphenylazo) 5 pyrazolone, melted at 111-1 14 C.

It should be noted that the couplers within Formula C, compounds within Formula B and amines may be selected and combined according to the novel processes of this invention to produce a large number of dye developers within the scope of this invention.

The following are examples of the photographic utilization of the dye developers of this invention and are given for purposes of illustration only.

EXAMPLE 8 A photosensitive element was prepared by coating a gelatin subcoated film base with a solution comprising 0.089 g. of 1- [4'-hydroquinonylpropylphenyl]-3-carbamyl-4-(3'-hydroquinonylphenylazo) 5-pyrazolene dissolved in 10 cc. of a solution of 2% cellulose acetate hydrogen phthalate in acetone. After this coating dried, a blue-sensitive silver iodobromide emulsion was applied and allowed to dry. This photosensitive element was exposed, and brought into super-posed relationship with an image-receiving element as an aqueous alkaline liquid processing composition comprising:

Water cc NaOH g 5.17 Hydroxyethyl cellulose (high viscosity) [commercially available under the trade name Natrosol 250] g 4.03 Sodium thiosulfate ....g 1.15 Benzotriazole g 0.5 N-benzyl-a-picolinium bromide g 2.3

was spread between said elements. The image-receiving element comprised a 2:1 mixture, by weight, of polyvinyl alcohol and poly-4-vinylpyridine on a baryta paper support. After an imbibition period of approximately 1 minute, the image-receiving element was separated and contained a yellow positive image.

EXAMPLE 9 EXAMPLE 10 The procedures described in Example 8 and 9 were repeated except that the dye developer was dispersed in a layer of gelatin. The coating solution from which the dye developer layer was coated was prepared by adding 0.64 g. of 1-(4-hydroquinonylpropylphenyl)-3-(N,n-hexylcarbamyl)-4-(3"-hydroquinonyl-phenylazo)-5-pyrazolone in 0.5 cc. of N-n-butylacetanilide and 1.0 cc. of cyclohexanone to 5 gm. of 10% gelatin solution, 1.8 cc. of water and 1.67 cc. of 5% Alkanol B. Emulsification was effected by high speed agitation in a Waring Blendor. 5 cc. of the resulting dye dispersion was added to 10 cc. of water containing small amounts of saponin and succinaldehyde, and ihen coated on the gelatin subcoated cellulose acetate film ase.

The dye developers of this invention possess a number of unobvious properties. Thus, for example, they develop more silver than closely related dve developers disclosed in the copending application of Milton Green, Ser. No. 130,468, filed Aug. 10, 1961 (now abandoned in favor of application Ser. No. 301,181, filed Aug. 9, 1963 and issued July 21, 1964 as US. Patent No. 3,141,772). The dye developers of this invention unexpectedly have been found to possess a substantially lesser tendency to fog, thereby requiring less antifoggant, particularly in monochrome diffusion transfer processes. Thus, with 1 phenyl-3-N-n-hexylcarbamyl-4-[p-(hydroquinonylethyl)-phenylazo]-5-pyrazolone, 2.3% benzotriazole is required as an antifoggant as compared to the fact that only 0.5 of benzotriazole is required with 1-(4'-hydroquinonylpropylphenyl) 3-(N-methylcarbamyl) -4-(3"- hydroquinonylphenylazo)-5-pyrazolone. The tendency to cause fog has been found to decrease as the size of the carbamyl group decreases; for example, a dye developer containing a group in the 3-position requires less antifoggant than the analogous dye developer containing a group O H %--I ICaHn The dye developers of this invention also exhibit less fading when exposed to light for prolonged periods, and less tendency to brown or discolor as an incident of such exposed to light, as compared with many previously known azo pyrazolon dye developers.

The dye developers of this invention have also been found to be unexpectedly superior to similar azo pyrazolone dye developers having only a phenyl radical in the 1-position of the pyrazolone ring, examples of which are disclosed in German Patent No. 1,036,640. In addition to developing substantially more silver, particularly in the absence of an accelerating developing agent, than, for example, 1-phenyl-3-(N,n-hexylcarbamyl)-4-(4'-hy droquinonylethylphenylazo)-5-pyrazolone, and also showing substantially greater light stability, the dye developers of this invention when used in diffusion transfer processes give transfer images of very low D min., high D max., and excellent control. When, for example, 1-(4'-hydroquinonylpropylphenyl) '3- (N,n hexylcar.bamyl)-4-(3"- hydroquinonylphenylazo)-5-pyrazolone or 1-(4'-hydroquinonylethylphenyl) 3 (N,n-hexylcanbamyl)-4-(3-hydroquinonylpropylphenylazo)=5-pyrazolone are employed in three-color diffusion transfer processes in place of 1 phenyl 3-'(N,n-hexylcarbamyl)-4-(4-hydroquinonylethylphenylazo)-5-pyrazolone in a multilayer negative also containing a magenta dye developer and a cyan dye developer, the resulting multicolor transfer image exhibits unexpectedly greater color separation and lower D min.

The dye developers of this invention are also useful in integral multilayer photosensitive elements for use in multicolor diffusion transfer processes. As an example of such photosensitive elements, mention may be made of the photosensitive elements disclosed and claimed in the copending U.S. application of Edwin H. Land and Howard G. Rogers, Ser. No. 565,135, filed Feb. 13, 1956, now U.S. Patent No. 3,345,163, issued Oct. 3, 1967, wherein at least two selectively sensitized photosensitive strata are superposed on a single support and are processed, simultaneously and without separation, with a single common image-receiving element. A suitable arrangement of this type comprises a support carrying a red-sensitive silver halide emulsion stratum, a green-sensitive silver halide emulsion stratum and a blue-sensitive silver halide emulsion stratum, said emulsions having associated therewith, respectively, a cyan dye developer, a magenta dye developer and a yellow dye developer. In one of the preferred embodiments of photosensitive elements of this type, the dye developers are disposed in separate alkalipermeable layers behind the photosensitive silver halide emulsion stratum with which they are associated.

The photosensitive elements within the scope of this invention may be used in roll film units which contain a plurality of photosensitive frames. The photosensitive elements of this invention are especially useful in composite roll film intended for use in a Polaroid Land Camera, or a similar camera structure such, for example, as the camera forming the subject matter of U.S. Patent No. 2,435,717, issued to Edwin H. Land on Feb. 10, 1948. In general, such composite roll films comprise a photosensitive roll, a roll of image-receiving material and a plurality of pods containing an aqueous alkaline processing solution. The rolls and pods are so associated with each other that, upon processing, the photosensitive element may be superposed on the image-receiving element and the pods may be ruptured to spread the aqueous alkaline processing solution between the superposed elements. The nature and construction of the pods used in such units are well known to the art. See, for example, U.S. Patent Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.

It will be noted that the liquid processing composition may contain one or more auxiliary or accelerating silver halide developing agents, such as p-methylaminophenol '(Metol); 2,4-diaminophenol (Amidol); benzylaminophenol; hydroquinone; a substituted hydroquinone such as toluhydroquinone, phenylhydroquinone, or 4'-methylphenylhydroquinone; or a 3-pyrazolidone such as l-phenyl-3-pyrazolidone. These silver halide developing agents are substantially colorless, at least in their unoxidized form. It is possible that some of the dye developer oxidized in exposed areas may be oxidized by an energy transfer reaction with oxidized auxiliary developing agent.

In addition, development may be effected in the presence of an ammonium compound, particularly a quaternary ammonium compound, in accordance with the processes disclosed and claimed in the copending application of Milton Green and Howard G. Rogers, Ser. No. 50,851, filed Aug. 22, 1960 now U.S. Patent No. 3,173,786, issued Mar. 16, 1965.

The dye developers of this invention may be used also in conventional photographic processes, such as tray or tank development of conventional photosensitive films, plates or papers to obtain black and white, monochromatic ortoned prints or negatives. By way of example, a developer composition suitable for such use may comprise an aqueous solution of approximately 1-2% of the dye developer, 1% sodium hydroxide, 2% sodium sulfite and 0.05% potassium bromide. After development is completed, any unreacted dye developer is washed out of the photosensitive element, preferably with an alkaline washing medium or other medium in which the unreacted dye developer is soluble. The expression toned is used to designate photographic images wherein the silver is re tained with the precipitated dye, whereas monochromatic is intended to designate dye images free of silver.

It should be noted that the dye developers of this medium are self-sufficient to provide the desired color image and do not depend upon coupling reactions to produce the desired color. They thus provide a complete departure from conventional photographic color processes in which the color is produced by a coupling reaction between a color former or coupler and the oxidized developing agent, as well as so-called auto-coupling processes in which color is obtained by a reaction of the oxidized developing agent with unoxidized developing agent.

It will be apparent that, by appropriate selection of the image-receiving element from among suitable known opaque and transparent materials, it is possible to obtain either a colored positive reflection print or a colored positive transparency. Likewise, the inventive concepts herein set forth are adaptable for multicolor work by the use of special photographic materials, for example, film materials of the type containing two or more photosensitized elements associated with an appropriate number of imagereceiving elements and adapted to be treated with one or more liquid processing compositions, appropriate dye developers suitable to impart the desired subtractive colors being incorporated in the photosensitized elements or in the liquid processing compositions. Examples of such photographic materials are disclosed in U.S. Patent No. 2,647,049 to Edwin H. Land.

As examples of useful image-receiving materials, mention may be made of nylon, e.g., N-methoxymethyl-polyhexamethylene adipamide, polyvinyl alcohol, and gelatin, particularly polyvinyl alcohol or gelatin containing a dye mordant such as poly-4-vinylpyridine. The image-receiving element also may contain a development restrainer, e.g., l-phenyl-5-mercaptotetrazole, as disclosed in the copending application of Howard G. Rogers and Harriet W. Lutes, Ser. No. 50,849, filed Aug. 22, 1960 and now U.S. Patent No. 3,265,498.

The dye developers herein set forth are also useful in the formation of colored images in accordance with the photographic products and processes described and 1 7 claimed in US. Patent No. 2,968,554, issued to Edwin H. Land on Jan. 17, 1961.

The novel compounds herein disclosed are also suitable for use as dyes for textile fibres, such as nylon.

In the preceding portions of the specification the expression color has been frequently used. This expression is intended to include the use of a plurality of colors to obtain black.

Since certain changes may be made in the above products, compositions and processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A compound of the formula:

i l Y-(X),,-Ar-N=N CN-Ra N HO N/ JIM-(M) nY wherein each Y is selected from the group consisting of orthoand para-dihydroxyphenyl radicals, each Ar is selected from the group consisting of phenylene or naphthalene groups, M and X are each lower alkylene groups, n and p each is an integer from to 1, inclusive, and each of R and R is selected from the group consisting of hydrogen and lower alkyl radicals, and further provided that R and R can be joined together to form with the nitrogen atom, a heterocyclic ring containing only carbon and said nitrogen.

2. 1 (4' hydroquinonylpropylphenyl) 3 (N,nhexylcar-bamyl) 4 (3" hydroquinonylphenylazo) 5- pyrazolone.

3. 1 (4 hydroquinonylethylphenyl) 3 [N ('yhydroxypropyl) carbamyl] 4 (3" hydroquinonylmethylphenylazo) 5 pyrazolone.

4. 1 (4' hydroquinonylethylphenyl) 3 (N,n-hexylcarbamyl) 4 (3" hydroquinonylpropylphenylazo)-5- pyrazolone.

5. 1 (4' hydroquinonylpropylphenyl) 3 (N,npropylcarbamyl) 4 (3" hydroquinonylphenylazo) 5- pyrazolone.

6. 1 (4' hydroquinonylpropylphenyl) 3 carbamyl- 4 (3" hydroquinonylphenylazo 5 pyrazolone.

7. 1 (4' hydroquinonylethylphenyl) 3 (N,n-hexylcarbamyl) 4 (4" hydroquinonylethylphenylazo) 5- pyrazolone.

References Cited UNITED STATES PATENTS 3,134,672 5/1964 Blout et a1. 260l62 X 3,183,089 5/1965 Simon 260-462 X 3,282,913 11/1966 Green 260-463 CHARLES B. PARKER, Primary Examiner.

D. M. PAPUGA, Assistant Examiner.

US. Cl. X.R. 9629; 2603l0 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,424 ,742 January 28, 1969 Arthur D. Jarrett It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4 lines 23 to 34, the formula should appear as shown below:

OH 0 H II I CH2 -N-N CNCH2"' CH2 c21 on CH2 CH Column 6, lines 23 to 37 the portion of the formula reading:

I I should read I N HO \N/ Column 10, lines 23 to 37, the portion of the formula reading 0 N I i should read N C N same column, line 40, "6 should read 4 line 58, "6 l should read lines 60 to 75, the left-hand portion of the formula should appear as shown below:

Column 11, line 2 (4 methy1-6 should read (6 methyl4 line 41, "4 dihydroxy" should read 4,5"trihydroxy lines 44 to 59, the portion of the formula reading:

0 H O H I I should read 0 N C-- N same column, line 62, after the bracket insert 5 Column 14, line 27, "3-N,n" should read 3- (N,n line 30, "compared" should read comprised line 39, "Example" should read Examples Column 15, line 8, "exposed" should read exposure line 9, "pyrazalon" should read pyrazalone Column 18, line 16, after "hydroquinonylphenylazo" insert a closing parenthesis.

Signed and sealed this 21st day of .April 1970.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents 

